Make clang-tidy work for dune-gdt

.vcsetup @ 194577ed

-Subproject commit 92db88698cf7655caff87cc3d7a1f3f11ea5518c
+Subproject commit 194577ed77af3d15f11c898f00084c4b1458cd74

cmake/modules/XtTooling.cmake

@@ -41,6 +41,16 @@ macro(ADD_TIDY)
     dune_symlink_to_source_files(FILES .clang-tidy)
     message(STATUS "adding tidy target")
     set(BASE ${PROJECT_SOURCE_DIR}/dune/xt/)
+    file(
+      GLOB_RECURSE
+      _files
+      "${BASE}/*.hh"
+      "${BASE}/*.h"
+      "${BASE}/*.cc"
+      "${BASE}/*.cxx"
+      "${BASE}/*.cpp"
+      "${BASE}/*.c")
+    set(BASE ${PROJECT_SOURCE_DIR}/dune/gdt/)
     file(
       GLOB_RECURSE
       _files